JP2000312121A - Noise filter - Google Patents

Abstract

(57) [Problem] To provide a noise filter for a power converter that requires a small space for mounting and is low-cost. SOLUTION: A desired number of strip-shaped dielectric chips are sandwiched and joined by two spiral coils having a rectangular cross section to form a spiral LC composite member, and a desired number of the spiral LC composite members are laminated. And a noise filter circuit formed by connecting the noise filter circuits, a desired number of the noise filter circuits are laminated via an insulating sheet, and a magnetic material is formed so that a magnetic circuit is formed at the center and the outer peripheral portion of the laminate. A noise filter comprising a filter circuit having an enclosure, a reactor function, and a capacitor function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise filter for a power converter for filtering switching noise generated by a switching operation of a semiconductor switch element constituting a power converter such as an inverter.

[0002]

2. Description of the Related Art A switching operation of a semiconductor switch element constituting a power converter such as an inverter is performed based on a pulse width modulated (PWM) drive signal having a carrier frequency of several kHz to several tens of kHz. By this switching operation, switching noise having a frequency component of several tens of kHz or more is generated from the power converter.

[0003] In recent years, among the frequency components of the switching noise, various legal regulations have been imposed on the power converter in order to suppress the adverse effect of the component of 100 kHz or more on external devices. A noise filter for power conversion is installed in this power converter.

As a conventional noise filter for power conversion of this type, a single reactor formed by winding an electric wire around a core made of ferrite, an amorphous alloy, a crystalline alloy, or the like, and a single capacitor formed of a film, a chip, or the like are used. Are connected in, for example, an inverted L-shape to constitute the filter, and the filter filters out switching noise generated due to the switching operation of the semiconductor switch element.

[0005]

However, a conventional reactor used as a noise filter of this type generally has a toroidal shape, and a capacitor has a pin insertion type and has a flat or cylindrical shape. However, when these are mounted on a printed circuit board inside the power converter, there is a problem that a mounting space larger than each individual volume is required.When mounting this filter by individual wiring, there are many connection points. However, there has been a problem that the method of fixing individual components is complicated.

An object of the present invention is to solve the above-mentioned problems and to provide a noise filter for a power converter that is smaller, thinner, and lower in cost.

[0007]

A first embodiment of the present invention is a noise filter in which a desired number of strip-shaped dielectric chips are sandwiched between two spiral coils having a rectangular cross section. A bonded spiral LC composite member is formed, a desired number of layers of the spiral LC composite member are laminated via an insulating sheet, and one of the spiral coils constituting the spiral LC composite member is mutually connected at an inner end of the spiral coil. The main circuit is connected to form a main circuit for passing a desired current, and the other spiral coil constituting the spiral LC composite member is connected to each other at an inner end of the spiral coil to pass a current based on high-frequency noise. Forming a noise filter circuit serving as an earth circuit to flow, and laminating a desired number of the noise filter circuits via an insulating sheet; A filter circuit laminate is formed, and the noise filter circuit laminate is surrounded by a magnetic body so that a magnetic circuit is formed at the center and the outer periphery thereof, thereby forming a filter circuit having a reactor function and a capacitor function. Is a noise filter.

A second embodiment of the present invention is the noise filter according to the first embodiment, wherein the spiral coil is formed by pressing a metal plate to a predetermined thickness.

In a third embodiment of the present invention, the spiral coil forming the main circuit is formed by stamping a metal plate to a predetermined thickness, and the spiral coil forming the ground circuit is formed by: A thin metal plate having the same shape as that of the spiral coil forming the main circuit except for the thickness and having a cross-sectional area capable of passing a desired current is formed by press punching. This is a noise filter according to the first embodiment, which is a feature of the present invention.

According to a fourth embodiment of the present invention, the spiral coil forming the main circuit is formed by pressing and punching a metal plate to a predetermined thickness. The noise filter according to the first embodiment is characterized by using a printed circuit board obtained by etching a copper foil in a same plane pattern as a spiral coil forming the main circuit.

In a fifth embodiment of the present invention, the spiral coil forming the main circuit is formed by press-punching a metal plate to a predetermined thickness. The noise filter according to the first embodiment, wherein a conductive paste material having the same plane pattern as a circuit spiral coil is applied to an insulating sheet, and the ground circuit functions as a resonance suppressing resistor.

In a sixth embodiment of the present invention, the strip-shaped dielectric chip has a conductive paste material applied in advance to a surface to be joined to the spiral core, and the conductive paste material is applied to the spiral core with a conductive adhesive. The first to first are characterized by being joined
It is a noise filter according to any one of the fifth embodiment.

According to a seventh embodiment of the present invention, in the strip-shaped dielectric chip, a conductive paste material is previously coated on a surface to be bonded to the spiral core, and the conductive paste material is bonded to the spiral core with a solder material. The first to fifth, characterized in that
The noise filter according to any one of the embodiments.

According to an eighth embodiment of the present invention, in the strip-shaped dielectric chip, a conductive paste material is previously coated on a surface to be joined to the spiral core, and the dielectric paste is joined to the spiral core with a resin material. This is a noise filter according to any one of the first to fifth embodiments.

According to a ninth embodiment of the present invention, any one of the noise filters of the first to eighth embodiments is housed in a plastic case and sealed with a resin material.
A noise filter unit characterized as being configured as a filter unit.

A tenth embodiment of the present invention is the noise filter unit according to the ninth embodiment, wherein the resin material is made of a polymer resin material filled with an inorganic filler at a predetermined ratio. It is.

An eleventh embodiment of the present invention comprises first to eighth
The noise filter of any one of the embodiments is housed in a plastic case, the other internal region is sealed with the silicone gel, and the inorganic filler is provided only in the region where the input / output terminals are arranged. The noise filter unit is characterized by being formed as a filter unit by being sealed with a polymer resin material filled at a ratio of (1).

A twelfth embodiment of the present invention is characterized in that the resin material is made of silicone gel, and a cover for fixing the input / output terminals is provided in a region where the input / output terminals are arranged. This is a noise filter unit according to the ninth embodiment.

The thirteenth embodiment of the present invention relates to the first to eighth embodiments.
Any one of the noise filters or the ninth to
The noise filter unit according to any one of the twelfth embodiments is connected to an input stage and / or
Alternatively, the power converter is connected to an output stage, is a common mode choke coil, and filters switching noise generated by the switching operation of the switching element.

The fourteenth embodiment of the present invention relates to the first to eighth embodiments.
Any one of the noise filters or the ninth to
Any one of the noise filter units according to the twelfth embodiment is connected to a circuit in a power converter having a switch element, and is used as a common mode choke coil to filter switching noise generated by a switch operation of the switch element. It is a power converter characterized by the above.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 5 are views showing a method for manufacturing a noise filter according to the first embodiment of the present invention. 1 to 5, a single-phase noise filter using two noise filter circuits will be described as an example.

FIG. 1 shows a first spiral LC composite member 5.
FIG. 9 is a view showing a step 1 for forming a 0; Where 1
Reference numerals a and 2a denote spiral coils that exhibit the function of an inductor.

Here, the spiral coil 1a forms a main circuit (for example, a circuit of a power converter). Therefore, it is necessary to have a current capacity necessary for passing the current of the main circuit. The spiral coil 1a can be formed, for example, by stamping a copper plate. In this case, for example, in order to make the current capacity about 1 A to 100 A, the necessary cross-sectional area is 0.1 to 10 mm ² , preferably 0.2 to ²⁰ mm ² . Spiral coil 1a
Can be formed in a range of about 0.2 to 5.0 mm.

In order to make connection with an external circuit at the outer end of the spiral coil 1a, a region 1ac which is drawn out by a fixed length to the outside so as to be mounted by inserting pins into a printed wiring board, for example. To form The inner end of the spiral coil 1a is a region 1an used for connection with a spiral coil forming another main circuit.

Next, the spiral coil 2a forms an earth circuit. The spiral coil 2a is a spiral coil 1a.
And may have the same shape and the same material. Preferably, the spiral coil 2a is a spiral coil 1a.
Should have the same plane pattern as the plane pattern. The cross-sectional area of the spiral coil 2a may be the same as or different from the cross-sectional area of the spiral coil 1a.

Here, the inner end of the spiral coil 2a is a region 2an used for connection with a spiral coil forming another earth circuit.

Reference numeral 3 denotes a dielectric chip. The dielectric chip 3 is connected to the spiral coils 1a and 2a to form a capacitor. The material of the dielectric chip 3 preferably has a large dielectric constant, such as BaTiO ₃ , Sr
Ferroelectric ceramic materials such as TiO ₃ and lead zirconate titanate (PZT) are more preferred. The thickness of this dielectric chip is in the range of 50 μm to 2 mm, preferably in the range of 100 μm to 1 mm, and more preferably in the range of 0.4 to 1 mm. Also, the width is equal to or less than the width of the spiral coil 1a. Further, the length is equal to or less than the length of one side of the spiral coil 1a.

The required number of the dielectric chips 3 are sandwiched between the spiral coils 1a and 2a at appropriate intervals.
And join. As described above, a first layer having the functions of an inductor and a capacitor for one layer is configured.

FIG. 2 shows a spiral LC composite member 50.
Spiral LC composite member 6 having the same function as
0 is a view showing a step 2 of manufacturing a No. 0. FIG. The second spiral LC composite member 60 is used to increase the inductance L and the capacitance C by making the spiral LC composite member multilayer.

The components 1b, 2b, and 3 of the second spiral LC composite member 60 each have a corresponding first
Of the spiral LC composite member 50 of FIG.
And may have the same material and shape as those of (3) and (3). First
Similarly, the spiral coil 1b forms a main circuit, and the spiral coil 2b forms a ground circuit.

The spiral coil 1b has a region 1bc at the outer end for connection to an external circuit. The inner end of the spiral coil 1b is a region 1bn for connecting to a spiral coil forming another main circuit.

Further, in order to connect to an external circuit, a region 2bc which is drawn out by a predetermined length outside is formed at one end of the spiral coil 2b so that it can be mounted, for example, by inserting a pin into a printed wiring board. . Further, an inner end of the spiral coil 2b is a region 2bn for connecting to a spiral coil forming another ground circuit.

As with the spiral LC composite member 50, a predetermined number of dielectric chips 3 and a spiral coil 1 for the main circuit are provided.
The spiral LC composite member 60 having the function of an inductor / capacitor is formed between the spiral coil 2b and the spiral coil 2b.

FIG. 3 is a diagram showing Step 3 for joining the spiral LC composite member 50 and the spiral LC composite member 60 to form the noise filter circuit 70.

The spiral LC composite member 50 and the spiral LC composite member 60 are laminated with the insulating sheet 4 interposed therebetween, and are joined at respective terminals inside both composite members. The main circuit inner terminal 1an of the spiral LC composite member 50 is joined to the main circuit inner terminal 1bn of the spiral LC composite member 60. As a joining method, soldering is performed via a metal piece or the like that compensates for a step. As a joining method, electric spot welding or pressure welding can be used.

The connection of the ground circuit is made by spiral LC
This is performed by connecting the ground circuit inner terminal 2an of the composite member 50 and the ground circuit inner terminal 2bn of the spiral LC composite member 60. As a connection method, an electric wire is used so as not to contact the main circuit.

Thus, the required inductance L
To form a noise filter circuit 70 including a coil having a number of turns for obtaining the above and a capacitor having a required capacitance C.

FIG. 4 shows noise filter circuits 71 and 7
FIG. 4 is a view showing a step 4 of laminating the magnetic material 2 through an insulating sheet 4 to form a noise filter circuit laminate, and sandwiching the noise filter circuit laminate between the magnetic material divided cores. The noise filter circuits 71 and 72 represent the two noise filter circuits 70 created in the steps 1 to 3. Noise filter circuit laminate (7
By sandwiching (the stacked body of 1, 4, and 72) between the magnetic material divided cores 5a and 5b, the inductance of the spiral coil inside 71 and 72 increases.

The magnetic divided cores 5a and 5b are E-shaped members joined to each other at the center of the noise filter circuit laminate and at the outer periphery of the inductor / capacitor. Therefore, the magnetic material split cores 5a and 5b
Forms a magnetic circuit around the noise filter circuit laminate. Further, the magnetic material split cores 5a and 5b are formed using a normal magnetic material, and are preferably formed using iron.

Here, two sets of noise filter circuits 70
(I.e., 71 and 72), the filter is laminated with the insulating sheet 4 interposed therebetween, and is sandwiched between the magnetic material divided cores 5a and 5b, so that a filter in which a common mode reactor and a grounding capacitor used for a single-phase line filter are combined is formed. Can be formed. Here, the upper noise filter circuit has the U phase, and the lower noise filter circuit has the V phase. Therefore, the main circuit connection portions (corresponding to 1ac and 2ac in 70 in FIG. 3) of the upper noise filter circuit become U-phase input / output terminals U1 and U2, respectively.
The ground circuit connecting portion (corresponding to 2bc in 70 in FIG. 3) becomes the ground terminal P. Similarly, the input / output terminals V1 and V2 and the ground terminal P of the lower noise filter circuit are shown.

Although not shown, if three sets of noise filter circuits 70 are laminated via an insulating sheet and sandwiched by magnetic cores, a three-phase common mode reactor and a grounding capacitor are provided. A composite line filter can be formed. In this case, the three noise filter circuits are U-phase, V-phase, and W-phase, respectively.

Next, FIG. 5 shows the magnetic material split cores 5a and 5a.
FIG. 9 is a view showing a step 5 of fixing the b to complete the single-phase noise filter 6 of the present invention. The noise filter 6 has a reactor function and a capacitor function. The magnetic substance split cores 5a and 5b can be fixed using a technique known in the art, for example, can be fixed using welding.

Next, the electrical properties of the noise filter of the present invention will be described with reference to FIG. FIG. 6 is an equivalent circuit diagram of the single-phase noise filter 6 of the present invention shown in FIG. In FIG. 6, since the spiral coil for the main circuit of each noise filter circuit has a predetermined length, between the U-phase and V-phase input / output terminals, that is, U1-U
A small inductance is continuously distributed between the two and between V1 and V2. Similarly, in the spiral coil for ground connected to the terminal P, minute inductance is continuously distributed. Since the dielectric chips 3 are spatially distributed between the spiral coil for the main circuit and the spiral coil for the earth of the spiral LC composite members 50 and 60 (see FIGS. 1 and 2), the main circuit U1-U2
And V1-V2 are connected to the respective ground circuits at fixed intervals through fixed capacitance. As a result, a distributed constant circuit having the function of a low-pass filter can be configured. Here, the low-pass filter has a cut-off frequency (for example, 10 kHz or more) necessary to filter switching noise generated due to a switching operation of a semiconductor switching element included in a power conversion device such as an inverter. Shall be.
The noise filter circuit of the present invention can have various cutoff frequencies by changing the material and / or shape of the dielectric chip and changing the capacitance and the inductance. The noise filter circuit of the present invention is preferably 10 to 150 kHz.
z, more preferably with a cutoff frequency of 10-50 kHz.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on.

FIG. 7 is a cross-sectional view of a structure in which a dielectric chip 3 is sandwiched between two sets of spiral coils 1a for a main circuit. That is, the same spiral coil 1a as the main circuit is used as the spiral coil 2a for the ground circuit. The spiral coil for the main circuit has a predetermined current capacity, and the current capacity can be changed by changing the thickness of a metal plate made of copper or the like constituting the coil and changing the cross-sectional area of the coil. The spiral coil may be formed by punching a metal plate made of copper or the like. In this case, a copper plate having a thickness of 0.2 to 1.0 mm is used. If a large current capacity is required and the current density becomes too high when a single spiral coil is used, or if the inductance and / or capacitance needs to be increased, multiple spiral coils can be used. In this case, a required number of spiral coils of the same shape are stacked and connected in parallel to reduce the current density, or reduce the required inductance and / or
Or a capacitance can be obtained. By using the same spiral coil 1a for the main circuit for the ground circuit, it is possible to eliminate the necessity of separately manufacturing a spiral coil for the ground circuit.

Next, a third embodiment of the present invention will be described with reference to FIG.
It will be described based on.

FIG. 8 shows a spiral coil 1a for a main circuit.
FIG. 3 is a cross-sectional view of a noise filter circuit in which a dielectric chip 3 is sandwiched between a grounding spiral coil 2a having a cross-sectional area different from 1a. Since the ground circuit spiral coil 2a only needs to guide the current of the noise component flowing through the dielectric chip 3 to the ground, the cross-sectional area can be made smaller than that of the main circuit coil pattern. In addition, when the thickness of the spiral coil 1a for the main circuit and the spiral coil 2a for the earth circuit are increased, a tensile force due to thermal stress is applied to the dielectric chip 3 at the center in the thickness direction, and the dielectric chip 3 may be torn. is there. Therefore, it is possible to make the thickness of the spiral coil 2a for the earth circuit only the necessary thickness, and to prevent a tensile force for thermal stress from being generated at the center of the dielectric chip 3. However,
The spiral coil 2a for the earth circuit is composed of the dielectric chip 3
Considering the capacitance of the capacitor constituted by the above, it is preferable that the capacitor has the same shape as the spiral coil 1a for the main circuit except for its thickness.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
It will be described based on.

FIG. 9 shows a spiral LC composite member 51 using a printed circuit board as a spiral coil for an earth circuit.
FIG. 3 is a schematic sectional view of FIG. Printed circuit board for ground circuit 7
The copper foil of the copper-clad laminate substrate is spirally etched in the same manner as the main circuit coil to form a ground circuit coil 7a. As the copper foil of the ground circuit coil 7a, a general thickness of 18 μm, 35 μm, 70 μm, or the like can be used. The dielectric chip 3 is disposed on the upper surface, and the spiral coil 1a for the main circuit is further laminated to form the spiral LC composite member 51.

By using a printed circuit board for the spiral coil for the earth circuit, the shape of the entire coil can be easily maintained. Further, since the printed board has lower rigidity than the copper plate, no tensile force due to thermal stress is generated at the center of the dielectric chip 3. Furthermore, since the substrate of the printed circuit board is an insulator such as glass epoxy, in order to increase inductance and capacitance, when a plurality of spiral LC composite members 51 are laminated, each spiral LC composite is used without using an insulating sheet. The insulation between the members 51 can be maintained.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
Description will be made based on 0.

FIG. 10 shows a spiral LC using a ground circuit coil formed of a conductive paste material on a dielectric substrate.
It is sectional drawing of a composite member. A conductive paste material is spirally coated on an insulating sheet 8 such as a glass epoxy substrate to form a conductive paste coil 9 for an earth circuit.
The dielectric chip 3 is arranged on the upper surface, and the spiral coil 1a for the main circuit is further laminated to form a spiral LC composite member.

As the conductive paste material, a material obtained by kneading silver powder, copper powder or the like with a binder is used. Since the conductive paste material has a higher resistivity than copper foil or the like, a resistance of about 1 Ω to 100 Ω is generated when a pattern is formed. When a noise current flows from the spiral coil 1a for the main circuit to the coil for the earth circuit via the dielectric chip 3, depending on conditions, a resonance phenomenon due to inductance and capacitance may occur, and the noise voltage may increase. Generally, in such a case, a resistor is inserted between the ground circuit coil and the ground wire to suppress the resonance phenomenon, but the resistor is formed by the conductive paste material of the present embodiment. In the case of a ground circuit coil, since the coil itself has a certain resistance value, it is possible to eliminate the need for introducing a resistor for suppressing the resonance phenomenon.

Next, a sixth embodiment of the present invention will be described with reference to FIG.
1 will be described.

FIG. 11 shows a state in which a conductive paste material is applied on the upper and lower surfaces of the dielectric chip 3 having electrodes 10 formed thereon, and the spiral coil 1a for the main circuit and the spiral coil 2a for the earth circuit are joined with the conductive adhesive material 11. It is sectional drawing of a state. Electrodes are formed on the joint surface of the dielectric chip 3 with the spiral coils 1a and 2a. The electrodes are thin layers of metal or conductive paste. When a conductive paste is used, for example, a paste containing Ag as a main component can be used, and as a forming method, application and curing of the conductive paste by screen printing can be used. When a metal is used, the electrode can be formed by a sputtering method using copper or the like, a vacuum evaporation method, or a plating method. The conductive adhesive 11 is applied to the electrode 10
After that, it is sandwiched between the spiral coil 1a for the main circuit and the spiral coil 2a for the earth circuit, and then heated and cured for bonding. By joining in this way, the spiral coil 1a for the main circuit and the spiral coil 2a for the ground circuit
A capacitor can be formed in between.

Next, a seventh embodiment of the present invention will be described with reference to FIG.
2 will be described.

FIG. 12 is a sectional view showing a state in which the dielectric chip 3 having the electrodes 10 formed on the upper and lower surfaces in advance, the spiral coil 1a for the main circuit, and the spiral coil 2a for the earth circuit are joined with the solder 12. The electrode 10 can be formed using the above materials. By joining in this manner, a capacitor can be formed between the spiral coil 1a for the main circuit and the spiral coil 2a for the earth circuit. Also, since a solder material is used, bonding can be performed in a short time.

Next, an eighth embodiment of the present invention will be described with reference to FIG.
3 will be described.

FIG. 13 is a sectional view showing a state in which the dielectric chip 3 having the electrodes 10 formed on the upper and lower surfaces in advance, the spiral coil 1a for the main circuit, and the spiral coil 2a for the earth circuit are joined by the resin material 13. The electrode 10 can be formed using the above materials. A liquid epoxy resin or the like is used for the resin material 13. After the resin material 13 is applied to the electrode 10, it is sandwiched between the spiral coil 1a for the main circuit and the spiral coil 2a for the ground circuit, and then heat-cured and adhered. Although a resin material such as an epoxy resin is insulative, it is considered that the electrodes 10 and the spiral coil are in contact with each other due to minute irregularities on their surfaces. Even if they are not in contact with each other, if the thickness of the resin material 13 is 1 to 2 μm, the resin material 13 functions as a dielectric of the capacitor, and the electrode 10, the spiral coil 1a for the main circuit, and the spiral coil for the ground circuit. 2a and a capacitor is formed. With any of the above, a predetermined capacitance can be obtained between the dielectric chip 3 and each of the spiral coils. The conductive adhesive is expensive due to the use of silver or the like, while the epoxy resin is inexpensive. Therefore, by using this embodiment mode, the cost can be reduced.

Next, a ninth embodiment of the present invention will be described with reference to FIG.
4 will be described.

FIG. 14 is a diagram showing a noise filter unit when the single-phase noise filter 6 of the present invention is housed in a plastic case 14. As shown in FIG. Plastic case 1
No. 4 is required to have properties such as insulation, robustness, and stain resistance. The material of the plastic case 14 is PBT
(Polybutylene terephthalate), PPS (polyphenylene sulfide) and the like can be used. By storing in a plastic case, protection from contamination such as dust and the like and insulation from external circuits can be achieved.

Next, a tenth embodiment of the present invention will be described with reference to FIG.

FIG. 15 is a sectional view showing a noise filter unit when the single-phase noise filter 6 of the present invention is housed in a plastic case 14 and sealed with a polymer resin material 15.

As the material of the plastic case 14, the above-mentioned materials can be used. As the polymer resin material 15, an epoxy resin, a urethane resin, a silicone resin or the like to which an inorganic filler such as quartz powder or alumina powder is added can be used. By using the polymer resin material 15 for sealing, it is possible to improve insulation properties, protect the inside from contamination such as dust, and prevent insulation deterioration.

The polymer resin material is required to have properties such as a coefficient of thermal expansion, high electrical insulation, high thermal conductivity, and high mechanical strength. In order not to cause distortion due to thermal stress, the thermal expansion coefficient of the polymer resin material 15 needs to be equal to those of the magnetic substance divided cores 5a and 5b. Also,
In order to dissipate the heat generated by the flow more effectively, it is necessary to have a large heat transfer coefficient, which can be achieved by the polymer resin material 15 containing a filler.

Further, in the present embodiment, the polymer resin material 15 having high mechanical strength fixes the lead terminals U1, U2, V1, V2, P of the noise filter 6. Therefore, external force is applied to these lead terminals U1, U2,
V1, V2, P, the internal noise filter 6
(For example, a spiral coil) can be prevented from being applied with an external force.

Next, an eleventh embodiment of the present invention will be described with reference to FIG.

FIG. 16 shows a case where the noise filter 6 is housed in a plastic case 14, sealed with silicone gel 16 to the vicinity of the opening, and a polymer resin material 15 is sealed on top of the silicone gel 16. It is sectional drawing which shows a filter unit. Various materials as described above can be used for the plastic case 14 and the polymer resin material 15.

As described above, by appropriately selecting a material to be sealed between the inside and the surface of the plastic case 14, the insulation can be improved, and the contamination such as dust from the opening to the inside can be prevented. Insulation deterioration can be prevented.

The silicone gel 16 having low elasticity
By using, without causing distortion due to thermal stress,
Mechanical reliability can be obtained. The polymer resin material 15 having high mechanical strength fixes the lead terminals U1, U2, V1, V2, and P of the noise filter 6. Therefore, external force is applied to these lead terminals U1, U2, V1, V2,
Even when P is applied, it is possible to prevent an external force from being applied to components (such as a spiral coil) of the internal noise filter 6.

Next, a twelfth embodiment of the present invention will be described with reference to FIG.

FIG. 17 shows a case where the noise filter 6 is housed in a plastic case 14, sealed up to the vicinity of the opening with a silicone gel 16, the opening is covered with a terminal fixing cover 17, and the lead terminals U 1, U2, V1,
FIG. 4 is a cross-sectional view illustrating a noise filter unit in which V2 and P are fixed with an adhesive 18. The plastic case 14 and the silicone gel 16 can use the various materials described above.

By fixing using the terminal fixing cover 17 and the adhesive 18 in this way, even if an external force is applied to the lead terminals U1, U2, V1, V2, P, an external force is applied to the internal noise 6. Can be prevented.
Further, contamination such as dust and the like from the opening to the inside can be prevented, and deterioration of insulation can be prevented.

As the material of the terminal fixing cover 17, a polymer resin material such as PBT or PPS which can be easily molded can be used.

As the adhesive 18, a general adhesive having an insulating property used in the art can be used.
For example, epoxy resin, polyester resin, acrylic resin, silicone rubber, and the like can be used.

Next, a thirteenth embodiment of the present invention will be described with reference to FIGS.

FIG. 18 shows a power converter 30 such as an inverter.
FIG. 4 is a circuit diagram in a case where the noise filter of the present invention is provided in the input stage of FIG. Here, three sets (for three phases) of noise filter circuits 100, 200, and 300 are used.

In the examples of FIGS. 1 to 17 described above, the structure of the single-phase noise filter 6 is shown using two sets of noise filter circuits. However, when the noise filter 6 is configured as a three-phase noise filter, In step 4 of FIG. 4, the noise filter circuit 300 can be easily realized by further mounting the noise filter circuit 300 below the noise filter circuit 72 via an insulating sheet.

The lead terminals of the noise filter circuit 100 thus configured are denoted by U1 and U2, the lead terminals of the noise filter circuit 200 are denoted by V1 and V2, and the lead terminals of the noise filter circuit 300 are denoted by W1 and W2. Then, the lead terminals U1, V1, W1 are connected to the input conductors 21a, 2a.
1b, 21c, and the lead terminals U2, V2, W2 are connected to the power converter 30.

By connecting in this manner, noise entering the power converter 30 from the input conductors 21a, 21b, 21c can be filtered, and switching noise generated by elements in the power converter 30 can be input. Conduction to the conductors 21a, 21b, 21c can be prevented.

FIG. 19 shows a power converter 30 such as an inverter.
This is an example in which three sets of reactor / capacitors 100, 200, and 300 according to the present invention are provided in the output stage.

The lead terminals U1, V1, W1 are connected to the power converter 30, and the lead terminals U2, V2, W2 are connected to the output conductors 22a, 22b, 22c.

By connecting in this manner, the switching noise generated by the elements in power converter 30 can be filtered, and the switching noise is transmitted from power converter 30 to output conductors 22a, 22b, and 22c. Can be prevented. The output conductors 22a, 22
The noise that enters the power converter 30 from 2b and 22c can be filtered.

FIG. 20 shows a power converter 30 such as an inverter.
Of the present invention, two sets of noise filter circuits 10
In this example, 0 and 200 are provided.

In the power converter 30, an input side is provided with a rectifier 31 for converting an alternating current inputted from the outside into a direct current, and a semiconductor switching element 32 is provided on the output side.
Is provided.

The lead terminals U1 and V1 are connected to the rectifier 3 on the input side.
1 and the lead terminals U2 and V2 are connected to the semiconductor switching element 32 on the output side.

By connecting in this manner, noise entering the semiconductor switching element 32 from the input terminals R, S, and T via the rectifier 31 can be filtered, and the switching noise generated by the semiconductor switching element 32 can be filtered. Is prevented from being transmitted to the input terminals R, S, and T.

[0088]

As described above, by using the configuration of the present invention, noise such as switching noise of the power converter can be sufficiently cut, and the current capacity of several amps or more required for the power converter can be sufficiently reduced. Can be provided.

Further, according to the present invention, a plurality of noise filter circuits are accommodated in a plastic case, and the gap is sealed with a polymer resin material or the like. With this, it is possible to provide a structure which can be easily mounted on a printed wiring board, and which is excellent in insulating property and mechanical reliability, and which is small and inexpensive.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method of manufacturing a first spiral LC composite member used for a noise filter according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing a second spiral LC composite member used for the noise filter according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a method of manufacturing a noise filter circuit used for the noise filter according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a method of manufacturing a noise filter circuit laminate used for the noise filter according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a method of manufacturing a completed noise filter of the noise filter according to the first embodiment of the present invention.

FIG. 6 is an equivalent circuit of the noise filter of the present invention, L
FIG. 2 is a circuit diagram showing a distributed constant circuit of C and a common mode reactor formed by the circuit.

FIG. 7 is a sectional view of a spiral LC composite member according to a second embodiment of the present invention, in which a dielectric chip is sandwiched between two main circuit spiral coils.

FIG. 8 is a sectional view of a spiral LC composite member according to a third embodiment of the present invention, in which a dielectric chip is sandwiched between a spiral coil for a main circuit and a spiral coil for a thin earth circuit.

FIG. 9 is a sectional view of a spiral LC composite member according to a fourth embodiment of the present invention, in which a dielectric chip is sandwiched between a spiral coil for a main circuit and a printed circuit board coil.

FIG. 10 is a sectional view of a spiral LC composite member using a coil formed of a conductive paste on an insulating sheet as a ground circuit coil according to a fifth embodiment of the present invention.

FIG. 11 is a cross-sectional view of a spiral LC composite member according to a sixth embodiment of the present invention, in which a main circuit coil and a ground circuit coil are joined to a dielectric chip coated with electrodes using a conductive adhesive. .

FIG. 12 is a cross-sectional view of a spiral LC composite member according to a seventh embodiment of the present invention, in which a dielectric chip coated with electrodes is joined to a main circuit coil and a ground circuit coil with a solder material.

FIG. 13 is a sectional view of a spiral LC composite member according to an eighth embodiment of the present invention, in which a dielectric chip coated with electrodes is joined to a main circuit coil and a ground circuit coil with a polymer resin material. .

FIG. 14 is a perspective view showing a noise filter unit according to a ninth embodiment of the present invention, in which a noise filter is housed in a plastic case and sealed with a resin material.

FIG. 15 is a cross-sectional view illustrating a structure of a noise filter unit according to a tenth embodiment of the present invention in which a noise filter is housed in a plastic case and sealed with a resin material containing an inorganic filler. is there.

FIG. 16 is a sectional view showing a noise filter unit according to an eleventh embodiment of the present invention, in which a noise filter is housed in a plastic case and sealed with a silicone gel.

FIG. 17 is a cross-sectional view showing a noise filter unit according to a twelfth embodiment of the present invention in which a noise filter is housed in a plastic case and a cover for fixing the noise filter is provided.

FIG. 18 is a circuit diagram showing a thirteenth embodiment of the present invention, in which a noise filter is provided in an input stage of a power converter.

FIG. 19 is a circuit diagram showing a thirteenth embodiment of the present invention, in which a noise filter is provided at an output stage of a power converter.

FIG. 20 is a circuit diagram showing a fourteenth embodiment of the present invention, in which a noise filter is provided inside a power converter.

[Explanation of symbols]

1a, 1b Spiral coil for main circuit 1ac, 1bc Outer terminal for main circuit 1an, 1bn Inner terminal for main circuit 2a, 2b Spiral coil for ground circuit 2bc Outer terminal for ground circuit 2an, 2bn Inner terminal for ground circuit 3 Dielectric chip 4 Insulation sheets 5a, 5b Magnetic material split core 6 Noise filter 7 Printed circuit board 7a Copper foil 8 Insulation sheet 9 Conductive paste coil 10 Electrode 11 Conductive adhesive 12 Solder 13 Resin material 14 Plastic case 15 Polymer resin material 16 Silicone gel 17 Terminal Fixing cover 18 Adhesive material 21a, 21b, 21c Input conductor 22a, 22b, 22c Output conductor 30 Power converter 31 Rectifier 32 Semiconductor switching element 50, 51, 60 Spiral LC composite member 70, 71, 72, 100, 200, 30 0 Noise filter circuit 400 Iron core U1, U2, W1 Input terminal V1, V2, W2, U, V, W Output terminal R, S, T Input terminal P Ground terminal

 ──────────────────────────────────────────────────続 き Continued from the front page F term (reference) 5J024 AA01 BA11 DA26 DA28 DA29 DA32 EA08 FA04

Claims (14)

[Claims] 1. A spiral LC composite member in which a desired number of strip-shaped dielectric chips are sandwiched and joined by two spiral coils having a rectangular cross section to form a spiral LC composite member having a desired number of layers. A spiral coil, which is laminated through an insulating sheet and forms one spiral coil composite member, is connected to each other at an inner end of the spiral coil to form a main circuit for allowing a main circuit to pass a desired current; A desired number of said noise filter circuits are formed by connecting the other spiral coils constituting the composite member to each other at an inner end of the spiral coils and forming a noise filter circuit serving as an earth circuit for passing a current based on high-frequency noise; Are laminated via an insulating sheet to form a noise filter circuit laminate, and the noise filter circuit laminate Enclosure of a magnetic material so that the magnetic circuit is formed in the heart and the outer portion, a noise filter, characterized in that to constitute a filter circuit having a function of function and the capacitor of the reactor. 2. The noise filter according to claim 1, wherein the spiral coil is formed by press-punching a metal plate to a predetermined thickness. 3. The spiral coil forming the main circuit is formed by pressing and punching a metal plate to a predetermined thickness, and the spiral coil forming the ground circuit is formed by removing the main circuit except for the thickness. The thin metal plate having the same shape as the spiral coil to be formed and having a cross-sectional area through which a desired current can flow can be formed by press punching. Noise filter. 4. A spiral coil forming the main circuit is formed by press-punching a metal plate to a predetermined thickness, and a spiral coil forming the ground circuit includes a spiral coil forming the main circuit. 2. The noise filter according to claim 1, wherein a printed circuit board obtained by etching a copper foil in a same plane pattern is used. 5. The spiral coil forming the main circuit is formed by press-punching a metal plate to a predetermined thickness, and the spiral coil forming the ground circuit is:
2. The noise filter according to claim 1, wherein a conductive paste material having the same plane pattern as the spiral coil for the main circuit is applied to the insulating sheet, and the ground circuit functions as a resonance suppression resistor. 6. The strip-shaped dielectric chip has a conductive paste material applied in advance to a surface to be joined to the spiral core, and is joined to the spiral core with a conductive adhesive. Item 6. The noise filter according to any one of Items 1 to 5. 7. The strip-shaped dielectric chip has a conductive paste material applied in advance to a surface to be joined to the spiral core, and is joined to the spiral core with a solder material. The noise filter according to any one of claims 1 to 5. 8. The strip-shaped dielectric chip has a conductive paste material applied in advance on a surface to be joined to the spiral core, and is joined to the spiral core with a resin material. The noise filter according to any one of claims 1 to 5. 9. A noise filter unit comprising the noise filter according to claim 1 housed in a plastic case and sealed with a resin material to form a filter unit. . 10. The noise filter unit according to claim 9, wherein said resin material is made of a polymer resin material filled with an inorganic filler at a predetermined ratio. 11. A side on which the noise filter according to claim 1 is housed in a plastic case, another internal region is sealed with the silicone gel, and an input / output terminal is arranged. A noise filter unit characterized in that only a region is sealed with a polymer resin material filled with an inorganic filler at a predetermined ratio to form a filter unit. 12. The resin material is made of silicone gel, and a cover for fixing the input / output terminals is provided in a region on the side where the input / output terminals are arranged.
The described noise filter unit. 13. An input stage and / or an output stage of a power converter having a switch element, wherein the noise filter according to any one of claims 1 to 8 or the noise filter unit according to any one of claims 9 to 12 is provided. And a common mode choke coil for filtering switching noise generated by the switching operation of the switching element. 14. The noise filter according to any one of claims 1 to 8 or the noise filter unit according to any one of claims 9 to 12 is connected to a circuit in a power converter having a switch element, and a common mode is provided. A power conversion device comprising a choke coil, and filtering switching noise generated in accordance with a switching operation of the switching element.